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Abstract:

The invention relates to a device and method for the defined longitudinal
shifting of an adjusting device which rotates along in a drive shaft,
along the center axis of the drive shaft. The solution according to the
invention is characterized in that a working chamber (12) is arranged at
the opposite end of the drive shaft (1), into which working chamber a
passage hole (7) arranged in the drive shaft (1) opens, wherein a working
piston (13) that operatively connects to the working chamber (12) is
arranged in such a way that, in the event of a pressure build-up in the
working chamber (12), the adjusting device (2) is variably moved against
the spring force of a restoring spring (10) by means of a radial piston
pump according to the invention that is arranged on the drive shaft (1).

Claims:

1. Apparatus for defined longitudinal displacement of an adjustment
apparatus (2) that rotates along with and within a drive shaft (1), along
the center axis of the work shaft, having a drive shaft (1) mounted in/on
a housing (3), in a bearing (4), driven by a drive element (5),
projecting into a work space (6) filled with pressurized medium, having a
through-hole (7), wherein wherein a spring chamber (8) is disposed in the
region of the through-hole (7), and wherein a spring stop (9) is disposed
on the adjustment apparatus (2), in such a manner that the adjustment
apparatus (2) is always brought back into a defined starting position
after every axial displacement, by means of a reset spring (10) that is
disposed in the spring chamber (8), and wherein a work chamber (12) is
disposed at the end of the drive shaft (1) that lies opposite the drive
element (5), into which chamber the through-hole (7) opens, wherein a
work piston (13) that enters into an active connection with the work
chamber (12) is disposed on the adjustment apparatus (2), in such a
manner that when pressure builds up in the work chamber (12), the
adjustment apparatus (2) is variably displaced, counter to the spring
force of the reset spring (10), and wherein a pump piston (18) having a
piston pass-through bore (19), which bore opens into a pressure channel
(17) disposed in the housing (3), is disposed in the housing (3), so as
to pivot, and wherein the drive shaft (1) is configured as an eccentric
shaft in the region of the pump piston (18), or wherein an eccentric
bushing (21) is disposed in the region of the pump piston (18), on the
drive shaft (1), so as to rotate with it, wherein a suction kidney (22)
connected with the work space (6), on the one hand, and a pressure kidney
(23) that lies opposite this suction kidney (22) on the circumference of
the eccentric mechanism, on the other hand, are disposed in the cam, in
each instance, wherein the pressure kidney (23) has a/multiple transfer
bore(s) (24) disposed in the eccentric mechanism, which bore(s)
connect(s) the pressure kidney (23) directly with the ring space (11),
and wherein a cylinder ring (25) having a piston bore (26) for the pump
piston (18) is disposed on the outer mantle of the eccentric bushing
(21), so as to rotate, in such a manner that when the eccentric bushing
(21) is rotating in the piston bore (26) of the cylinder ring (25), the
pump piston (18) "works," i.e. moves vertically up and down in
oscillating manner, and wherein a valve seat (27) is disposed in the
housing (3), into which seat the pressure channel (17) opens, on the one
hand, and a return line (28) connected with the work space (6) opens, on
the other hand, and wherein a solenoid valve (29) is disposed in the
valve seat (27), between the pressure channel (17) and the return line
(28).

2. Method for defined longitudinal displacement of an adjustment
apparatus (2) that rotates along with and within a drive shaft (1), by
means of the apparatus according to claim 1, wherein the adjustment
apparatus (2) is displaced in defined manner along the center axis of the
work shaft (1), by means of varying the pressure in the pressure channel
(17).

3. Apparatus for defined longitudinal displacement of an adjustment
apparatus (2) that rotates along with and within a drive shaft (1),
according to claim 1, wherein a pivot cylinder (15) provided with a
dead-end bore (14) that is closed off toward the work space (6) is
disposed in the housing (3) on the work space side, the open bore end
(16) of which cylinder opens into the pressure channel (17), wherein a
pump piston (18) having a piston pass-through bore (19) is disposed on
the pivot cylinder (15), so as to rotate, and this piston pass-through
bore (19) opens into the dead-end bore (14) of the pivot cylinder (15) by
way of a through-passage bore (20) disposed in the pivot cylinder (15) in
the region of the piston pass-through bore (19).

4. Apparatus for defined longitudinal displacement of an adjustment
apparatus (2) that rotates along with and within a drive shaft (1),
according to claim 1, wherein the transfer region into the suction kidney
(22) is configured as a ring channel (30), adjacent to which, toward the
work space (6), a ring-shaped gap filter (31) is disposed.

5. Apparatus for defined longitudinal displacement of an adjustment
apparatus (2) that rotates along with and within a drive shaft (1),
according to claim 1, wherein piston rings (32) are disposed on the
outside circumference of the region of the pump piston (18) that is
displaceably mounted in the piston bore (26) of the cylinder ring (25).

Description:

[0001] The invention relates to an apparatus and a method for defined
longitudinal displacement of an adjustment apparatus that rotates along
with and within a drive shaft, along the center axis of the work shaft.

[0002] In the state of the art, apparatuses for defined longitudinal
displacement of adjustment apparatuses that rotate along with and within
the drive shaft, i.e. along the center axis of the drive shaft, are
previously described in connection with the regulation of liquid or
gaseous volume streams in pumps or compressors.

[0003] For example, DE 2110776 A1 describes a flow work machine having
regulatable impeller cross-sections, in which machine an adjustment
spindle that rotates along, driven by way of the blade wheel, is disposed
within the drive shaft, which spindle can be longitudinally displaced in
the drive shaft by means of a piston drive provided with a regulator.

[0004] This solution has the disadvantages that it requires a very large
construction space, is material-intensive and cost-intensive, furthermore
has a structure that is very susceptible to failure, does not switch to
maximal power automatically if the regulation fails, and furthermore
carries a high risk with regard to the aspect of work safety.

[0005] In other designs, the adjustment apparatus and the work spindle are
disposed not within one another in the axial direction, as described
above, but rather disposed to lie flush with and opposite one another.

[0006] Such a design is previously described in DE 37 32 038 C2. In this
design, the adjustment apparatus is once again carried along by the drive
shaft, by way of the blade wheel. In this solution, the adjustment
apparatus can be displaced in defined manner, by means of a partial
vacuum, by way of a separate activation element disposed on the pump
housing, lying opposite to the drive means of the drive shaft, a V-belt
pulley.

[0007] Failure of the regulation brings about the result that in this
solution, a switch to maximal pump power takes place automatically, by
means of a reset spring.

[0008] However, this design also requires a very large construction space
in connection with the pressurized lines, the required pressure
regulator, etc., and is therefore also material-intensive and
cost-intensive.

[0009] In other solutions, adjustment apparatuses in the form of
pressure-spring-impacted thermostats/wax elements were integrated on the
drive shaft, with significantly less effort and a smaller construction
volume.

[0010] Such solutions are previously described, for example, in U.S. Pat.
No. 4,828,455 or also in DE 199 01 123 A1.

[0011] The significant disadvantage of these solutions, however, consists
in that they react too slowly for active regulation of the conveyed
coolant amount, and by no means are able to influence the engine
temperature in such a way, after it has warmed up (i.e. in "continuous
operation"), that not only the pollutant emissions but also the friction
losses and also the fuel consumption could be clearly reduced in the
entire work range of the engine.

[0012] For this reason, it was proposed, for example in DE 10 2008 046 424
A1, to use electromagnetically activated adjustment apparatuses, i.e. to
displace rotating components using a magnetic coil disposed in the pump
housing.

[0013] In this solution, a magnet armature is rigidly disposed in the
magnetic field of a magnetic coil integrated into the pump housing, at
the end of the adjustment apparatus that lies opposite the adjustment
element, by means of which the adjustment apparatus guided in the drive
shaft can be linearly displaced, under the effect of the electromagnetic
field of the magnetic coil.

[0014] The installation of such electromagnetically activated adjustment
elements, for example in the vicinity of the turbocharger, necessarily
requires cooling of the magnetic coil (and thereby a relatively large
"construction space"), because the magnetic coil would be destroyed at
temperatures starting from 120° C.

[0015] This relatively large "construction space" that is in turn
necessarily required, also for the magnetic coil disposed in a pump
housing, according to DE 10 2008 046 424 A1, is diametrically opposed to
the very limited "installation space" that is available in the engine
compartment.

[0016] Furthermore, a disadvantage of this solution is that production and
installation are very cost-intensive, because the functional modules
cannot be uniformly produced for multiple construction sizes, i.e.
standardized, and therefore have to be produced separately for every pump
housing size.

[0017] The invention is therefore based on the task of developing an
apparatus and a method for defined longitudinal displacement of an
adjustment apparatus that rotates along with and within a drive shaft,
along the shaft center axis of the drive shaft, particularly in
connection with the regulation of liquid or gaseous volume streams in
pumps or compressors, which eliminates the aforementioned disadvantages
of the state of the art, and, in this connection, guarantees active and
reliable regulation of the longitudinal displacement over the entire
range of the speed of rotation and temperature, with very little work
effort, which is furthermore suitable even for high-rpm applications and
can be used even under disadvantageous general thermal conditions, such
as in the vicinity of a turbocharger, for example, while having a small
and compact structure, working robustly, and optimally utilizing the
existing construction space, furthermore can be produced, at the same
time, in simple and cost-advantageous manner, in terms of production and
assembly technology, always guarantees a high level of operational safety
and reliability, and is suitable as a unit even for different pump sizes,
i.e. can be produced in "standardized" manner, and, at the same time, can
be integrated into any desired regulation circuits, in simple and
cost-advantageous manner.

[0018] According to the invention, this task is accomplished by means of
an apparatus and a method for defined longitudinal displacement of an
adjustment apparatus that rotates along with and within a drive shaft,
along the center axis of the work shaft, in accordance with the
characteristics of the independent claims of the invention.

In this connection, the figures show:

[0019] FIG. 1: a schematic representation of the principle of action of
the invention for defined longitudinal displacement of an adjustment
apparatus that rotates along with and within a drive shaft;

[0020] FIG. 2: a possible design embodiment of the solution according to
the invention, for defined longitudinal displacement of an adjustment
apparatus that rotates along with and within a drive shaft, in section,
in a side view.

[0021] This solution according to the invention, for defined longitudinal
displacement of an adjustment apparatus 2 that rotates along with and
within a drive shaft 1, along the center axis of the work shaft, shown in
FIG. 1 in the form of a schematic representation of the principle of
action of the invention, in an axial section, and in FIG. 2 in the form
of one of the possible design embodiments of the solution according to
the invention, in section, in a side view, having a drive shaft 1 mounted
in/on a housing 3, in a bearing 4, driven by a drive element 5,
projecting into a work space 6 filled with pressurized medium, having a
through-hole 7 that accommodates the adjustment apparatus 2, is
characterized in that a spring chamber 8 is disposed on the drive-side
end, in the through-hole 7, and that a spring stop 9 is disposed on the
drive-side end of the adjustment apparatus 2, in such a manner that the
adjustment apparatus 2 is always brought back into a defined starting
position after every axial displacement, by means of a reset spring 10
that is disposed in the spring chamber 8. It is essential to the
invention, in this regard, that a work chamber 12 is disposed at the end
of the drive shaft 1 that lies opposite the drive element 5, into which
chamber the through-hole 7 opens, whereby a ring space 11 is disposed
between the through-hole 7 and the adjustment apparatus 2 disposed in
this bore, whereby a work piston 13 that enters into an active connection
with the work chamber 12 is disposed at the end of the adjustment
apparatus 2 that lies opposite the spring stop 9, in such a manner that
when pressure builds up in the work chamber 12, the adjustment apparatus
2 can be variably displaced in the through-hole 7, counter to the spring
force of the reset spring 10.

[0022] It is characteristic, in this connection, that a pump piston 18
having a piston pass-through bore 19, which bore opens into a pressure
channel 17 disposed in the housing 3, is disposed in the housing 3, so as
to pivot.

[0023] A significant characteristic of the invention, in this connection,
consists in that an eccentric bushing 21 is disposed in the region of the
pump piston 18, on the drive shaft 1, so as to rotate with it, in which
bushing a suction kidney 22 connected with the work space 6, on the one
hand, and a pressure kidney 23 that lies opposite on the circumference of
the eccentric bushing 21, on the other hand, are disposed, whereby the
pressure kidney 23 has a transfer bore 24 disposed in the eccentric
bushing 21, which bore opens into a further transfer bore 24 disposed
adjacent to the drive shaft 1, and thereby connects the pressure kidney
23 directly with the ring space 11.

[0024] It is also essential to the invention, in this connection, that a
cylinder ring 25 having a piston bore 26 for the pump piston 18 is
disposed on the outer mantle of the eccentric bushing 21, so as to
rotate, in such a manner that when the eccentric bushing 27 is rotating,
the pump piston 18 "works" in the piston bore 26 of the cylinder ring 25,
i.e. moves vertically up and down in oscillating manner, and pumps medium
contained in the work space 6 into the pressure kidney 23, by way of the
suction kidney 22, when the solenoid valve 29 is closed, which medium is
conveyed from there into the work chamber 12, by way of the transfer
bores 24 and the ring space 11.

[0025] In this connection, it is characteristic that a valve seat 27 is
disposed in the housing 3, into which seat the pressure channel 17 opens,
on the one hand, and a return line 28 connected with the work space 6
opens, on the other hand, whereby a solenoid valve 29 is disposed in the
valve seat 27, between the pressure channel 17 and the return line 28.

[0026] When the drive shaft 1 is rotating and the solenoid valve 29 is
closed, the pump piston 18, which moves vertically up and down in the
piston bore 26 of the cylinder ring 25, in oscillating manner, according
to the invention, causes medium contained in the work space 6 to be
pumped into the pressure kidney 23, by way of the suction kidney 22, and
from there to be conveyed into the work chamber 12 by way of the transfer
bores 24 and the ring space 11.

[0027] It is also advantageous, in this connection, that piston rings 32
are disposed on the outside circumference of the region of the pump
piston 18 that is displaceably mounted in the piston bore 26 of the
cylinder ring 25, which rings guarantee a high degree of effectiveness of
the arrangement according to the invention, with little production and
assembly effort.

[0028] In FIG. 2, one of the possible design embodiments of the solution
according to the invention is now shown, in the design of a coolant pump
for motor vehicles, having a setting slide 35 that can be displaced by
way of the adjustment apparatus 2, which slide serves for varying the
"effective" blade width of the vane wheel.

[0029] The drive shaft 1, which is mounted in the housing 3 in a bearing
4, driven by a drive element 5, projecting into a work space 6 filled
with pressurized medium, in which shaft a through-hole 7 that
accommodates the adjustment apparatus 2 is disposed, is particularly
characterized in that a pivot cylinder 15 provided with a dead-end bore
14 that is closed off toward the work space 6 is disposed in the housing
3 on the work space side, the open bore end 16 of which cylinder opens
into a pressure channel 17, whereby a pump piston 18 having a piston
pass-through bore 19 is disposed on the pivot cylinder 15, so as to
rotate, and this piston pass-through bore 19 opens into the dead-end bore
14 of the pivot cylinder 15 by way of a through-passage bore 20 disposed
in the pivot cylinder 15 in the region of the piston pass-through bore
19.

[0030] It is also characteristic, in this connection, that the transfer
region into the suction kidney 22 that is open at a side wall is
configured as a ring channel 30, adjacent to which, on the outside, i.e.
toward the work space 6, a ring-shaped gap filter 31 is disposed, so that
in this region, passage of cooling medium from the pump interior 14 into
the ring channel 30 is possible, whereby penetration of undesirable
particle sizes of chips and sand grains is prevented by means of the
setting of the filter gap of the ring-shaped gap filter 31.

[0031] If now, in this concrete embodiment according to the invention, as
shown in FIG. 2, the drive shaft 1 is put into rotational movement by way
of the drive element 5, a belt pulley, then at the same time, the
eccentric bushing 21 disposed on the drive shaft 1 so as to rotate with
it, which bushing is provided with a suction kidney 22 that is open
toward the side wall on the vane wheel side, on the one hand, and with a
pressure kidney 23 that is open toward the passage bore 7 in the drive
shaft 1, on the other hand, is put into rotational movement.

[0032] In this connection, the cylinder ring 25 that is mounted on the
outer mantle of this eccentric bushing 21, so as to rotate, is put into
lifting movements with the piston bore 26 disposed in it.

[0033] The work piston 13 disposed in the piston bore 26, with its piston
pass-through bore 19 disposed in the work piston 13, easily oscillates
around the pivot cylinder 15 provided with the dead-end bore 14, when the
eccentric bushing 21 is rotating; the piston pass-through bore 19 opens
into the dead-end bore 14 by way of a through-passage bore 20 disposed in
the pivot cylinder 15.

[0034] The vane wheel bushing of the vane wheel of the conveying pump 33,
shown in FIG. 2, disposed on the drive shaft 1, by means of a disposed in
the vane wheel as an insert, lies against the eccentric bushing 21 in the
embodiment shown in this FIG. 2, whereby the vane wheel forms a gap
filter 31 with the adjacent face side of the cylinder ring 25, adjacent
to which the ring channel 30 is disposed on the eccentric bushing side.

[0035] The (open side wall of the) suction kidney 22 is disposed laterally
adjacent to this ring channel 30.

[0036] As a result, continuous passage of medium, by way of the
ring-shaped gap filter 31, from the work space 6 into the ring channel
30, and, by way of the latter, into the suction kidney 22, which is open
on the side wall side in the region of the ring channel 30, is
guaranteed.

[0037] As is shown in FIGS. 1 and 2, a conveying pressure is built up in
connection with the conveying pump 33, not only in the work space 6, and,
for example, at the same time, also in a conveying circuit 34.

[0038] The rotating drive shaft 1 according to the invention now also
brings about defined "conveying" of the medium, according to the
invention, from the work space 6, by way of the suction kidney 22, into
the piston bore 26, and from there, by way of the piston pass-through
bore 19, and in an embodiment as shown in FIG. 2, further by way of a
through-passage bore 20 and a dead-end bore 14 of a pivot cylinder 21,
into the pressure channel 17 regulated by the solenoid valve 19.

[0039] When the solenoid valve 29 is open, the medium conveyed in this
manner flows back into the work space, by way of the solenoid valve 29
and a return line 28, and the setting slide 35 shown in FIG. 2 lies
against the vane wheel of the conveying pump 33 in its rearmost end
location position.

[0040] In this connection, the gap dimensions between the housing 3 and
the setting slide 35 are dimensioned in such a manner that an inflow of
conveying medium from the work space 6 into the ring channel 30 is
guaranteed even in the rearmost end position.

[0041] When the solenoid valve 29 is closed, a "dynamic pressure" is built
up from the piston bore 26 all the way to the pressure channel 17, which
brings about the result that medium pumped into the piston bore 26 by the
suction kidney 22 is pressed into the pressure kidney 23, and from there
gets into the ring space 11 by way of the transfer bores 24, enters into
the work chamber 12 by way of this space, and there brings about a
displacement of the work piston 13, counter to the spring force of the
reset spring 10, and, in this connection, as shown in FIG. 2, activates a
setting slide 35, for example.

[0042] The stroke of the pump piston 18 in the piston bore 26 of the
cylinder ring 25 amounts to approximately 1 mm to 2 mm per revolution in
the present exemplary embodiment. As a result of the arrangement
according to the invention, even very small conveying amounts are already
sufficient for precise displacement of the work piston 13, which is
rigidly disposed on the spring-loaded adjustment apparatus 2.

[0043] The method according to the invention for defined longitudinal
displacement of an adjustment apparatus 2 that rotates along with and
within a drive shaft 1, by means of the apparatus described above, is
characterized, in this connection, in that the adjustment apparatus 2 can
be displaced in the longitudinal direction in defined manner, by means of
a solenoid valve 29 by varying the pressure in the pressure channel 17.

[0044] When the solenoid valve 29 is "open," i.e. without current in the
present exemplary embodiment, the piston pump according to the invention
conveys medium, here coolant, back into the work space 6 by way of the
return line 28 of the solenoid valve 29, in "pressure-free" manner, as
has already been explained.

[0045] If now the return flow of the medium conveyed by the piston pump
according to the invention into the return line 28 and thereby back into
the work space 6 is throttled or actually completely prevented by means
of the solenoid valve 29, then the cooling medium conveyed by the
arrangement according to the invention is pressed into the work chamber
12 by way of the ring space 11, and thereby the pressure in the ring
space 11 and also in the work chamber 12 is first increased, in step-free
manner.

[0046] In this connection, the medium pressed into the work chamber 12 in
this manner brings about a defined pressure application to the work
piston 13 shown in FIG. 2 of the adjustment apparatus 2 spring-loaded by
the reset spring 10, which pressure can be adjusted (by way of the
solenoid valve 29), and thereby a defined longitudinal displacement of
the adjustment apparatus 2 that rotates along with and within the drive
shaft 1.

[0047] This defined application of pressure to the cross-sectional surface
area of the work piston 13 by way of the solenoid valve 29 now makes
precise translational displacement of an adjustment apparatus 2 that
rotates along with and within the drive shaft 1 possible, as shown in the
exemplary embodiment according to FIG. 2, for example, and thereby the
adjustment of a displaceable setting slide 35 that is disposed on this
rotating adjustment apparatus 2 and rotates with it, for variation of the
"effective" blade width of a vane wheel of a conveying pump 33.

[0048] In this connection, the arrangement according to the invention
guarantees active and reliable regulation of the longitudinal
displacement of the adjustment device 2 over the entire range of speed of
rotation and temperature, in all the embodiments presented, at very low
drive power.

[0049] Because of the forced operation by means of the eccentric drive,
according to the invention, of the pump according to the invention, the
present solution is suitable even for applications at high speeds of
rotation.

[0050] The solution according to the invention has a very small
construction and optimally utilizes the available construction space, is
very compact and works very robustly and reliably.

[0051] In this connection, the present solution can be produced in simple
and cost-advantageous manner, in terms of production and assembly
technology, and always guarantees great operational reliability.

[0052] Even under very disadvantageous thermal general conditions, such
as, for example, in the vicinity of a turbocharger in a motor vehicle,
and, at the same time, with greatly limited installation space, the
solution according to the invention guarantees optimal cooling with
minimized construction volume and great reliability, as a result of the
provision of a solenoid valve 29 that is simultaneously cooled by the
conveying medium.

[0053] Even in the event of failure of the regulation mechanism,
"fail-safe" operation can be implemented as described below, by means of
the solution according to the invention.

[0054] In the non-powered state, the solenoid valve 29 opens, the pressure
in the pressure channel 17 and in the work chamber 12 drops, and
spring-loaded "movement back" to the rearmost work position of the
regulating slide 7 takes place, in the embodiment of the invention as
shown in FIG. 2, for example into "emergency operation," i.e. a
"fail-safe" position.

[0055] When the adjustment apparatus 2 "moves back," the medium contained
in the work chamber 12, and also the medium being pumped by the
arrangement according to the invention at this time, is passed into the
return line 28 by way of the pressure channel 17 and the solenoid valve
29 (which is open when the adjustment apparatus 2 moves back), and from
there back into the work space 6.

[0056] When the adjustment apparatus 2 is "held" in an intermediate
position, the flow through the solenoid valve 29, for example, is
released just to such a point that only the medium being pumped by the
arrangement according to the invention flows out of the pressure channel
17 into the return line 28, by way of the solenoid valve 29, and from
there back into the work space 6.

[0057] The solution according to the invention is also particularly
characterized by its very short construction, in terms of its
longitudinal expanse, which is able to optimally utilize even very small
construction spaces.

[0058] Furthermore, the solution according to the invention can be
"standardized" as a unit and therefore can be used even for different
pump sizes.

[0059] In this connection, the solution according to the invention can
also be integrated into different regulation circuits, in simple and
cost-advantageous manner.